The first round of games are usually an indication for teams on what needs to be improved upon, what needs tweaking and what just needs to be left alone. But most of the time, the first game can prove to be an omen for things to come.

Here are the five things we learned this week and what to watch out for in Week 2.

The Kids Are All Right

Opening weekend featured the debuts and returns of future stars in this league. As many predicted, some of them were off to a great start, such as Atlanta Falcons' WR Julio Jones and Washington Redskins’ QB Robert Griffin III.

Jones came blazing out of the gate Week 1 with 6 REC/108 YDS/2 TD, and he’s well on his way to break his touchdown total (10) from last year.

In Week 2, Jones and the Falcons face the Denver Broncos, who gave up 209 passing yards to a Pittsburgh Steelers receiving corps that was still gelling under Todd Haley’s system. This Falcons team has been together for two years now, the Broncos defense will find it hard to contain such weapons as Jones, Roddy White, Tony Gonzalez and Michael Turner. Expect Julio to have a big game.

Robert Griffin III also had an impressive outing for the Washington Redskins in his NFL debut. He completed 73.1 percent of his passes, accumulating 320 passing yards in the process, along with two touchdowns.

Griffin is poised to have another great performance in Week 2, going up against the St. Louis Rams, who had the worst pass defense last week (346 passing yards allowed). He may not produce the same numbers, but he’ll be all right.

The Kids Are Not All Right

While some of the NFL’s young players were flourishing, others got off to a rough start. Most notably were highly touted draft picks back in April.

Cleveland Browns RB Trent Richardson carried the ball 19 times for only 39 yards. He looked lost and at times he was off the field when the Browns were trying to get down the field. Not an inspiring sight when he is considered the team’s next franchise player.

Ryan Tannehill, one of the Miami Dolphins' stars of Hard Knocks this past summer, had an equally disappointing outing. He threw three interceptions, with a majority of his passes thrown right at the defense. Marc Sessler from NFL.com reports that Mike Sherman has already gone on record saying Tannehill needs to perform better.

There is a lot of pressure on these guys' shoulders, so expect both to bounce back and produce better numbers in Week 2.

But no disappointment was bigger than that of Indianapolis Colts QB Andrew Luck. Even though he threw for 309 yards and one touchdown, most of his productivity came during garbage time, and at points he seemed forced, causing three turnovers.

James Irsay is still high on his prospects, and he should be. He traded a future Hall of Fame quarterback for him. But if Luck does not perform, Irsay will soon regret not taking Griffin with the first pick.

Mixed Feelings on Replacement Referees

Prior to the regular season we were hoping for the professional referees to come back. With Week 1 over, some want them back even more.

The replacements were mainly criticized for missing calls. According to Gil Lebreton of The Modesto Bee, retired linesman Terry Gierke noticed that in the Dallas Cowboys–New York Giants game, there were eight missed calls in the first half, whereas professional referees would only miss four.

Several players have already expressed their displeasure at the new referees. The most notable case is Mario Williams who complained to The Buffalo News that numerous “hands to the face” penalties that were missed on New York Jets tackle Austin Howard.

But overall the refs will get better with experience, and their performance was not all that bad. According to Chase Stuart of the New York Times, only 206 penalties were called this week, which was around the average of 208 in the opening week of the NFL since 2002. Penalty yardage was up due to the high number of pass interference calls, but that, too, was identical to norms of “professional” referees.

Referees may be receiving much criticism, but if their Week 1 performance is any indication, they will act more within the historical averages and with more experience they should be able to manage the games more acutely in Week 2.

The Jets Are Fine...For Now

During the preseason, many critics lambasted the New York Jets for only scoring one touchdown through four games. So when they put up 48 points against the “retooled” Buffalo Bills defense, that came as a shock to many.

This shock is both unwarranted and warranted.

Their lack of touchdowns did not matter because it was the preseason. Teams do not put out their best effort and usually play backups. The Jets were primarily trying to get a feel for how their team would look come the regular season, as well as practicing the Wildcat with Tim Tebow.

However, Mark Sanchez has not impressed the coaching staff enough to lock up the starting quarterback position. On paper he has gotten better year by year. His quarterback rating went from 63.0 in 2009 to 75.3 in 2010, to 78.2 in 2011.

But Sanchez and the Jets offense have come up short in crunch time, and if they can’t fix that soon, don’t expect them to play well against the Steelers in Week 2.

Game of the Week: Chicago vs. Green Bay

Even though it is early in the season, this is an important matchup.

The Chicago Bears are coming off a 30-10 win against the rebuilding Indianapolis Colts. Their defense was reading the opposing offense well, and their own offense was clicking. The introduction of Brandon Marshall into the passing attack has paid big dividends.

Already with one touchdown and 139 receiving yards, the combination of QB Jay Cutler and Marshall will help the Bears get down the field. Matt Forte also came off a great Week 1 performance, keeping good to the four-year deal he signed this offseason.

The Green Bay Packers are at the other end of the spectrum. Coming off a loss to the San Francisco 49ers at home, the Pack are looking to redeem themselves against a divisional foe. Even though the Bears looked potent in Week 1, the Pack still have the best quarterback in the league, and with all his options, they should have no problem giving the Bears’ defense a handful.

But each side has its liabilities. Greg Jennings’ groin injury could sideline him, which will reduce Rodgers’ options in the passing attack. On the other side of the ball, Urlacher’s injury may hold him back a bit, but that won’t stop him from playing at 100 percent.

If this past Sunday is any indication, the Packers won’t be able to solve Urlacher and the defense, allowing the Bears to come away with the win.